Inclusion Criteria:
1. Sign written informed consent and be able to comply with the program's visit schedule and related procedures.
2. Male or female subjects, age 18\~75 years.
3. Histologically or cytologically confirmed advanced colorectal cancer.
4. Subjects who have progressed on standard therapy, who are unsuitable for standard therapy, who do not have standard therapy, or who have refused standard therapy.
5. Adequate organ function.
6. At least one measurable lesion (target lesion) per RECIST v1.1.
7. Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0 or 1.
8. Life expectancy of 3 months or more.
9. Female subjects of childbearing age or male subjects whose partners are female subjects of childbearing age agree to strictly adopt effective contraceptive measures throughout the entire treatment period and 6 months after the treatment period.
Exclusion Criteria:
1. Women who are pregnant or lactating, or intending to become pregnant before, during, or within 6 months after the last dose of study drug.
2. Active epileptic seizures or active central nervous system (CNS ) metastases and so on.
3. Clinically significant cardiovascular or cerebrovascular disease.
4. Interstitial pneumonia, pulmonary fibrosis, pneumoconiosis, drug-associated pneumonia, and radiation pneumonitis requiring steroid hormone or other therapy, as well as history of severe abnormal lung function or other forms of restrictive lung disease.
5. History of allergies, asthma, atopic dermatitis.
6. Subjects with large amounts of pleural effusion or ascites.
7. Active autoimmune disease requiring systemic therapy within 2 years prior to first dose.
8. Known history of allogeneic organ transplantation and allogeneic hematopoietic stem cell transplantation.
9. Subjects with known or suspected hypersensitivity to the study drug and any excipients.
10. Subject has a prior history of significant toxicity associated with immune checkpoint inhibitor administration or Bevacizumab that requires permanent discontinuation.
11. Subjects with unresolved \> Grade 1 toxicity associated with any prior antineoplastic therapy, with the exception of persistent Grade 2 alopecia, peripheral neuropathy and so on.
12. Active uncontrolled bleeding or known bleeding tendency.
13. Any major surgery within 4 weeks prior to the first dose of study drug.
14. Known positive Human Immunodeficiency Virus (HIV) test, active hepatitis B, hepatitis C (HCV), tuberculosis.
15. Severe/active/uncontrolled infection, infection requiring systemic intravenous antibiotic therapy, or unexplained fever within 2 weeks prior to the first dose of study drug.
16. Diagnosis of another malignancy within 5 years prior to the first dose, exceptions include radically treated basal cell carcinoma of the skin, squamous cell carcinoma of the skin, and/or radically resected carcinoma in situ, as well as post-radical localized prostate cancer, and papillary thyroid cancer.
17. Presence of any disease, treatment or laboratory test abnormality, or history or current evidence of substance abuse that, in the judgment of the investigator, may compromise the safety of the subject, interfere with obtaining informed consent, affect subject compliance, or compromise the safety evaluation of the study drug.
